1. Field of the Invention
The present invention relates generally to design and operation of internal combustion engines. More particularly, the present invention relates to engine rotation speed pulsation damping within the design and operation of internal combustion engines.
2. Description of the Related Art
When operating internal combustion engines, and in particular when operating internal combustion engines a s employed within transportation vehicles, it is common to experience engine rotation speed pulsation. Engine rotation speed pulsation typically derives from inherent combustion pulsation characteristics when operating internal combustion engines. Similarly, engine rotation speed pulsation is undesirable when operating internal combustion engines insofar as engine rotation speed pulsation, particularly at an internal combustion engine idle speed within a transportation vehicle, contributes to transportation vehicle noise, vibration and harshness which in turn detrimentally influence customer satisfaction with a transportation vehicle.
It is thus desirable in the art of internal combustion engine design and operation to provide methods and systems that provide internal combustion engines with damped engine rotation speed pulsation.
Various methods, apparatus and systems have been disclosed within the art of internal combustion engine design and operation for providing internal combustion engines with damped engine rotation speed pulsation.
Included among the methods, apparatus and systems, but not limited among the methods, apparatus and systems, are methods, apparatus and systems disclosed within: (1) Nishizawa et al., in U.S. Pat. No. 5,213,077 (a method, an apparatus and a system that employ a fuzzy human logic inference rule set to provide for gain adjustment within a PID controller that controls an air/fuel ratio when operating an internal combustion engine in order to dampen an engine rotation speed pulsation when operating the internal combustion engine); and (2) Stuntz et al., in U.S. Pat. No. 6,039,028 (a method, an apparatus and a system which employ an algorithm comprising a pure feedback engine speed control component and a learning feedforward engine speed control component in order to dampen an engine rotation speed pulsation when operating an internal combustion engine).
Desirable in the art of internal combustion engine design and operation are additional methods, apparatus and systems that provide for engine rotation speed pulsation damping when operating internal combustion engines.
It is towards the foregoing object that the present invention is directed.
In accord with the object towards which the present invention is directed, there is provided by the present invention a method and a system that employ a PID controller to control a supplemental torque source connected to a crankshaft of an internal combustion engine, to provide to the crankshaft of the internal combustion engine a supplemental torque which in turn provides engine rotation speed pulsation damping when operating the internal combustion engine. Within the present invention, values for a desired engine rotation speed, an observed engine rotation speed and the supplemental torque supplied to an internal combustion engine are continuously supplied to the PID controller which employs a control algorithm, such as to continuously vary PID control parameters which controls the supplemental torque source, to converge the PID control parameters such as to damp an engine rotation speed pulsation within the internal combustion engine.